Machine for looping coil springs



Dec. 18, 1962 c. F. PENNY MACHINE FOR 1.00pm; con. SPRINGS 6 Sheets-Sheet 1 Filed April 24. 1959 INVENTOR m as 5 ATTORNEY Dec. 18, 1962 c. F. PENNY MACHINE FOR LOOPING con. SPRINGS Filed April 24; 1959 6 Sheets-Sheet 2 ATTO RNEY w w 6 W 15k Q;

Dec. 18, 1962 c. F. PENN-Y 3,069,024

MACHINE FOR LOOPING COIL SPRINGS Filed April 24, 1959 6 Sheets-Sheet 3 ATTORNEY Dec. 18, 1962 c. F. PENNY 3,069,024

MACHINE FOR LOOPING COIL SPRINGS Filed April 24, 1959 6 SheetsSheet 4 sa e / r ATTORNEY Dec. 18, 1962 c. F. PENNY 3,069,024

- MACHINE FOR LOOPING COIL SPRINGS Filed April 24. 1959 e Sheets-Sheet 5 72 INVENTOR ATTORNEY Dec. 18, 1962 C. F. PENNY MACHINE FOR LOOPING COIL SPRINGS Filed April 24. 1959 6 Sheets-Sheet 6 c lsc arges war a s a la" UP gig-fig [1- 5 TIP/9N5 FE}? .BA REEL .9

P/acea fa sup ar?" work 6/9 4 Pefrac fed Va i- 40 i /05" i 55 CONUU/ 7' SL/UES C LAM P TOOL C'enfer 7 /aap I INVENTOR "6505M a 5 ATTORNEY United States Patent 3,069,024 MACHINE FOR LOOPING COIL SPRINGS Chester F. Penny, Bridgeport, Conm, assignor to Sleeper & Hartley, Inc., Worcester, Mass, a corporation of Massachusetts Filed Apr. 24, 1959, Ser. No. 808,728 16 Claims. (Cl. 214-1) This invention relates to improvements in machines for looping the ends of coil springs, one such machine being shown in my US. Patent No. 2,703,592, issued March 8, 1955.

Heretofor'e in the aft of bending the end convolution of a coil spring so that it will serve as an anchorage loop or hook or assume some other special shape of terminal at the end of the wire of the coil spring, high speed of production and desirably uniform precision of loop formation have been hampered by the necessity of placing the coil spring in an exact predetermined rotary position about its own axis in relation to the paths of movement of tools which bend the end convolution to form a loop and in relation to certain other tools that are operative to hold the body of the spring with requisite firmness while the bending is taking place whereby the loop shall be disposed in accurate predetermined relation to the diameter of the main body of the spring coil.

It is an object of the present improvement to accomplish such placement and holding of coil springs in much more rapid succession than heretofore has been possible and with greater precision than has heretofore been accomplished in fully automatic spring coil looping machines, namely machines that are capable of feeding themselves automatically and rapidly with coil springs one by one from a stored supply of such springs and then completing the formation of loops on both ends of each coil spring by pure automation without any manual attention up to the time the coil spring, looped on both ends, is discharged in finished condition from the machine.

A further object of the invention is to solve particular problems thathave been encountered heretofore in attempts automatically to position and to hold coil springs of very small sizes of wire while being looped by machine. The particularly difficulty in working on these smaller sizes of springs has been due in part to their feeble resistance to distortion making it difiicult to hold and bend the end convolutions without distorting the main body of the coil spring.

Another object of the improvements is to produce a machine capable of looping both ends of a coil spring, particularly in the above-mentioned small sizes with precision at the previously unheard of production speed 0 more than 3,500 coil springs per hour. 9

These and other objects of the invention will appear in fuller particular from the following description of the invention as embodied in a successfully operating machine of preferred construction, having reference to the appended drawings wherein:

FIG. is a front view ofamachine incorporating my present improvements in duplicate upper station and lower station mechanisms for looping respectively opposite ends of a coil spring by automation, inclusive of feeding the coil spring to the looping stations and discharging the springs therefrom.

3,069,024 Patented Dec. 18, 1962 FIG. 1a is a fragmentary view on an enlarged scale taken on the plane 1a1a in FIG. 1 looking in the direction of the arrows. 1

FIG. lb is a fragmentary View on an enlarged scale taken on the plane lb-ib in FIG. 1 looking in the direc tion of the arrows.

FIG. 2 is a right side elevation of the machine shown partially in section on the plane 22 in FIG. 1.

FIG. 2a is a fragmentary plan view taken in section on the plane 2a2a in FIG. 2.

FIG. 3 is a perspective view of the back of the machine showing the source of power for motivating all the mechanisms appearing in FIGS. 1 and 2. 7

FIG. 4 is an enlarged view of one of the spring feeding and positioning units of the machine showing parts broken away to expose the construction, the parts being positioned as related at the end of the spring positioning action of the mechanism.

FIG. 4a is an enlarged fragmentary view taken in section on the plane 4a4a in FIG. 2 looking in the direction of the arrows.

FIG. 5 is a fragmentary view showing the spring engaging parts of FIG. 4 in partially elevated position.

FIG. 6 is a view similar to FIG. 5 showing the spring engaging parts in fully elevated position.

FIG. 7 is a view taken in section on the plane 7-7 looking downward in FIG. 4.

FIG. 8 shows the spring positioning mechanism of FIGS. 5 and 6 in its operating relationship to the parts of the machine which convert the end convolution of the coil spring into an anchorage loop.

FIGS. 9 and 10 are views taken in section respectively on the planes 9-9 and 10-10 in FIG. 8 looking in the direction of the arrows.

FIGS. 11 to 14, inclusive, show on a still further enlarged scale the successive stages of action of the loop forming tools.

FIG. 15 is an enlarged elevational view taken in section on the plane 1515 in FIG. 1 looking in the direction of the arrows showing the mechanism which actuates the retractable locating gage against which the end of thecoil spring is positioned in the upper looping station and the actuating mechanism for the coil spring transfer mechanism whereby a coil spring with one end already looped in the upper station is advanced downward to a duplicate loop station at which the opposite end of the same coil spring becomes looped.

7 FIG. 16 is a view take in section looking downward on the plane 16--16 in FIG. 15.

FIG. 17 is a view taken in section looking downward on the plane 1717 in FIG. 15.

FIG. 18 is a diagram showing the relative times of synchronized action of all the cooperative parts.

General Characteristics In the art of forminga loop or book at the end of a coil spring madeof helically wound wire it is old practice to separate the end convolution of the spring coil from the remainder of the coil and turn it into applane paralleling or coincident with the axis of the coil so as to form a hook or loop for anchoring the spring in use; Such hook of loop may vary from a half turn to,- say, one and-a-quarter turns of the already curved convolution of the spring coil. I

Feed and Positioning Mechanism The main organization of the working mechanism of the machine comprises duplicate upper and lower work stations, designated in general S and S, which are in vertical alignment one above the other. In these separate stations an anchorage loop or hook is formed successively on respectively opposite ends of a coil spring 12 that becomes automatically transferred from the upper to the lower work station. But since a second end loop is formed on an advanced spring at the lower station 8' at the same time that a first loop is being formed on a following spring at upper Station S, each coil spring becomes equipped with a loop on both ends at the same high rate of production speed that the coil springs are successively delivered to Station S from the chute 14.

A hopper 13 of the conventional vibratory type well known in the art and therefore not herein necessary to illustrate in detail serves to keep an end-to-end supply of work springs 12 in the top portion of the chute 14 waiting to be released one-by-one and continue their sliding down the chute at spaced intervals of time determined by the cooperative actions of a hold-back gate 15 and an escapement or release gate 16. The spring delivery action of gates 15 and 16 occurs in synchronism with the cycles of movement of the loop forming parts of the mechanism as is hereinafter explained in greater detail.

The coil springs thus supplied automatically by chute 14 drop by gravity one-by-one in timed relation out of the lower end of the chute through a funnel 17 into the hollow of a vertical tubular conduit 25 which is rotated and simultaneously caused to slide up or down by mechanism next to be described. A rotation permitting and slide permitting bearing for conduit 25 is afforded in the frame bracket 36 that is fixed on the front of vertical frame plate 37. Another similar bearing is afforded in vertical alignment therewith in the frame bracket 45 which is also fixed on the front of frame plate 37. An upward facing shoulder 24 on conduit 25 never travels upward beyond the lower face of bracket 36, and a pinion 47 whose hub 49 is fixed to conduit 25 by a set screw 44 never travels downward beyond the upper face of bracket 36, wherefore the vertical reciprocative movement of conduit 25 cannot exceed that dimension by which the distance of conduit shoulder 24 from the pinion 47 exceeds the vertical thickness of bearing bracket 36. In practice the vertical travel of conduit 25 is somewhat less than such excess dimension. Suitably it may be in the neighborhood of .075" for which amount of vertical movement there is ample clearance between pinion 47 with its hub 49 and the two bearing brackets 36, 45.

The vertical movement of conduit 25 is effected by a shifter yoke 48 whose somewhat forked end engages a circumferential groove in pinion hub 49. Arm 48 is clamped fixedly on a vertical plunger rod 51 having slide bearing in both brackets 36 and 45. This rod, in unison with the shifter arm, is constantly urged upward by thrust spring 52 which bears between the arm and the bracket 36. The upward limit of travel of shifter arm 48 is set and determined by adjustment of a stop screw 50 having threaded engagement through bracket 45. Rod 51 is periodically depressed endwise by a rocker arm 53 acting against the opposition of spring 52 in appropriately timed relation to the cycle of action of the machine as hereinafter described. Rocker arm 53 is fixed on a frame ournaled shaft 54 which at the rear of frame plate 37 4 carries the fixed arm 55 that is lifted and lowered by crown cam 2 of the power source shown in FIG. 3.

Also effected in properly timed relation to the cycle of machine action is a rapid spinning motion of conduit 25 in alternate rotary directions caused by oscillatory movement of a gear segment 46 whose teeth are in slidable mesh with pinion 47 and which is pivotally mounted at 11 on the machine frame. Gear segment 46 is united with a small pinion 43 which in turn is driven by another gear segment 42 mounted to oscillate on a frame carried pivot 41 and impelled so to do by forward and backward reciprocation of a horizontal link 40 extending through an opening 10 in frame plate 37 and operated by a bell crank 39 fixed on the top end of a long vertical shaft 56 that is pivoted in frame brackets 57, 57' and fixedly carries near its lower end a similar bell crank 39'. Shaft 56 is tensioned by a spring 56:: to cause the bell crank roller 39a to follow the peripheral contour of power cam 3 which, like power cam 2, is fixed on the vertical power shaft 1 of FIG. 3. Shaft 1 is driven unidirectionally at suitable speed through a speed reducing transmission 19 powered by pulley 20 that may be belt driven by any suitable prime mover. Shaft 1 can also be rotated by the hand wheel 21.

Below bracket 36 the periphery of conduit 25 contains three longitudinal keyways 22 of equal angular spacing, each keyway having slidably nested therein a cam key 23 of the shape shown in FIG. 4. The upper outwardly projecting lug or head 31 of each key 23 turns freely in an annular space 34 forming a thrust resistive raceway in a three-ply block 35 fixed as an appendage to the bottom surface of frame bracket 36. This prevents vertical shifting of key 30 despite freedom of the key heads 31 to revolve in unison with conduit 25 while leaving the conduit free to reciprocate vertically in the manner aforesaid.

The lower end 30 of each key 23 forms a laterally directed lug which remains at a constant vertical level during up and down movement of conduit 25 and cooperates as a cam to be wiped by the inner edge or cam surface of one of three work spring grasping fingers 26. Fingers 26 depend swingably from their pivotal mountings at 33 on a three-armed collar serving as hinge brackets 32 carried fixedly on the periphery of conduit 25. The

keyways 22 at their bottom ends may be cut through the cylindrical wall of conduit 25 at their lower ends to accommodate swinging of the inwardly directed bottom terminals of fingers 26 to their positions shown in FIG. 5 wherein they slightly underlie the vertical passageway 38 through conduit 25 which guides the coil spring 12 and thereby serve to arrest a coil spring on its way downward through the conduit.

Each finger is resiliently urged to swing about its pivot 33 toward its innermost position shown in FIG. 5 by an individual torsion spring 29 but periodically is forced to swing outward to its radially retracted position shown in FIG. 4 during the upper portion of the vertical travel of conduit 25 and likewise forced to swing radially outward to its retracted position shown in FIG. 6 during the lower portion of the vertical travel of conduit 25. In either of these outward retracted positions shown in FIGS. 4 and 6 the fingers 26 clear the passageway 38 and release the coil work spring to drop downward by gravity.

Operation of the Feeding and Positioning Mechanism Reference may now be had to the timing diagram in FIG. 18 for a more complete understanding of the cooperative action of the aforedescribed parts of the mechanism which feed the work spring 12 rapidly into its arrested position in FIG. 8 ready to be looped.

A cycle of machine operation will be understood to start at the left end of the chart in FIG. 18 and progress with time toward the right. The contour of the chart curves indicates time of movement but not necessarily extent of movement of the machine parts that operate on the coil work spring.

- Power cams 2 and 3 are so shaped and so fixed in relative position on power shaft 1 at the beginning of its cycle of rotation that they cause the following sequence of movements of the work spring grasping clutch fingers 26. With its passageway 38 empty, conduit with clutch fingers 26 immediately begins to rise and continues rising throughout the first 60 degrees of power shaft revolution. Simultaneously conduit 25 and the clutch fingers 26 are continually spunabout without useful function. At an intermediate stage of the rising movement of the clutch fingers each cam wiper 36 is encountered by a slanting notch 26 in the cam surface on the inner edge of its corresponding clutch finger. Thereupon the clutch fingers are momentarily swung radially inward by springs 29 so as partially to overlap passageway 38. At that instant a single coil spring to be looped has been released from chute 14 in time to drop downward in the passageway 38 and meet the clutch fingers endwise whereupon its falling is momentarily checked. Continued rising of the clutch fingers causes them to cam outward from the wipers 30 so that the clutch fingers are caused to spread again. This permits the temporarily arrested work spring 12 to drop further into endwise contact with the gage 27 where it is supported in arbitrary rotary position. This temporary arresting of the falling work spring on its way down through passageway 38 has been found to solve a serious problem of wasted time consumed by excessive bouncing of the work spring were it to drop unhindered the entire vertical length of passageway 38 and then rebound upward away from gage 27.

After an additional 40 to degree turning of power shaft 1, FIG. 18 indicates that the conduit 25 with clutch fingers 26 begins to descend. During such descent the clutch fingers spin around in the opposite rotary direction and the cam wipers 30 are again encountered by the finger notches 26 while the fingers are thus spinning and descending. At this stage the fingers 26 contract radially under the urge of springs 29, until they softly grasp the periphery of the coil work spring and yieldingly urge it to rotate while simultaneously urging it downward gently against the gage 27. Thus the free end of the wire that forms the endmost'convolution of the work spring is reliably and very quickly brought to rest in a definite rotary position predetermined by its abutment against the radial shoulder 28 on the top surface of the gage. The final portion of the helically twirling descent of clutch fingers 26 returns conduit 25 to its lowermost starting position after a total of about 175 degrees of turning of power shaft 1, which is nearly a half of the full cycle of power shaft revolution. By this time the rotary spinning of conduit 25' has ceased as indicated by the timing diagram and the coil work spring is left stationary and dwelling on the gage 27in accurate rotary position rela= tive to the rectilinear paths of movement of the looping tools for having the designed disposition of loop imparted to the work spring. Power cams 2 and 3 then cease to act upon the feeding and positioning mechanism until the beginning of the next cycle of revolution of the continually turning power shaft 1.

When supported on gage 27 the work spring 12 is surrounded in the lower portion of its length by a stationary, frame mounted well afforded by bushing 66 into which at least the lower end of the Work spring drops when released from the grasp of clutch fingers 26. At this point the gage 27 must be bodily displaced from beneath well 66 before the loop forming tools can go to Work because it occupies the space into which the looping tools must move.

Gage Operating Mechanism Gage 27 is adjustably mounted on a carrier arm 88 that swings about frame pivot 87 between its full line and broken line positions indicated in FIG. 15. It is caused so to swing by backward and forward endwise reciprocative movement of a link 89 that has pivotal, push-pull connections with carrier arm 88. Link 89 extends rearward through an opening in frame plate 37 and has pivotal connections with a frame pivoted bell crank 90 operated by the inverted crown cam 4 fixed on shaft 1 of the power system. See FIGS. 15 and 16.

As there are two gages 27 alike in the respective looping mechanisms of the upper and lower work stations S and S, their simultaneous and like movements are offected by a vertical pitman line 91 pivotally connected to the bell cranks 90, 90' in each looping station. Upper bell crank 9t, and hence both bell cranks 9d, 9d, are constantly biased upward by the frame anchored spring 92 which urges bell crank 90 against cam 4.

Timed Operations of the Gage Again rpferring to FIG. 18 it is indicated that the work spring supporting and position determining gage 27 becomes swung into its operative position directly beneath well 66 simultaneously with the rising movement of conduit 25. It attains such position ready to receive the work spring before the conduit begins to descend. It is also evident from the timing diagram that the gage remains in position supporting the work spring until after conduit 25 has completed its descent, during which clutch fingers 26 have placed the bottom end of the work spring in accurate rotary position against the gage. Thus gage 27 does not begin its retractive movement until power shaft 1 has completed some 200 degrees of its cycle of revolution at which time the tools that are to form the loop are successively impelled into action by power mechanism next to be described.

Looping Tools and Their Power Drive There are four tools alike in each of the upper and lower work stations S and S which participate in the loop forming operation. These are numbered 62, 63, 64 and 63 in FIGS. 8-14. Each pair of the said like tools is motivated simultaneously in the timed relationship to one another diagramed' in FIG. 18 by a different one of four power cams 6, 5, 7 and 8 fixed on power shaft 1. Each looping tool is mounted to reciprocate in a horizontal rectilinear path while carried by a slide 70 guided in a supporting way 53 fixed on the front surface of frame plate 37. As the construction of these ways may be conventional it will not be necessary herein to described them in detail. They appear endwise in FIG. 2. The slides 79 are alike as shown in FIGS. la and lb each comprising a leading end 131 on which the tool is mounted by bolts 132 and a forward extending lug 13-3 spaced from the tool carrying end of the slide. In the case of all tools there is an eyebolt 134 for each slide which occupies a clearance hole in lug 133 and a clearance hole coaxial therewith in the leading end 131 of the slide. In the case of the slides which carry tools 62, 63 and 68 respectively, the eyebolt 134 is fixed lengthwise in the slide by separated nuts 135 each in screw threaded engagement with the eyebolt. In the case of the slide which carries tool 64, as shown in FIG. lb, the nuts 135 are tightened together on the screwthreads of the eyelet like lock nuts and there is a flanged clearance bushing 136 through which the eyebolt is free to slide lengthwise. A yieldable thrust spring 69 constantly exerts axial tension between the nuts 135 and the flange of clearance bushing 136 sothat the eyebolt is able to shift inward of the slide against the opposition of spring 69 when the strength of spring 6? is overcome.

The work spring holding tool 62 comprises a thin blade-like tongue disposed. broadside upward. On the bottom surface of tongue 62 there is fixed a depending shoulder 67 whose purpose is hereinafter explained. In FIG. 9 it is shown that the blade-like tool 62 is not only thin but is somewhat wider from edge to edge than the diameter of the coil work spring 12. Power cam 6 is so shaped and fixed in such rotary position on power shaft 1 that it comesinto action to motivate holding. tool 62 before the other three looping tools start to move. The timing of this action in relation to the movements of the work spring positioning parts which precede it and in relation to the movements of the other three looping I tools which follow it is evident from the timing diagram of FIG. 18.

As best shown in FIG. 3, earn 6 operates tool 62 by means of a cam follower arm 106 fixed on a vertical shaft 107 journaled in on upper frame bearing 111 and having also fixed thereon a crank arm 108 that reaches forward past the edge of frame plate 37. At the front of the frame plate, crank arm 108 is pivotally coupled by a pitman link 109 to the before described eyebolt 134 of the slide that carries tool 62. Follower arm 106 is constantly pressed against the periphery of cam 6 by spring 110. Shaft 107 extends downward and at its bottom end is journaled in a lower frame bearing 112 and thereat fixedly carries a crank arm 108 which duplicates and swings in unison with crank arm 108. Its pitman link 109 connects it with blade-like tool 62' in the lower station S of the looping mechanisms.

The spur-shaped looping tool 63 initiates the loop forming separation of the end convolution of the work spring from the adjacent convolutions. It stands on edge and is considerably thinner than the diameter of the coil work spring. This tool rides horizontally in a narrow relatively deep channel sunk from the top edge of the underlying anvil tool 64 as shown in FIG. 10. The top edge of tool 63 slides in a notch cut upward in the wall of well 66 and rides into closely underlapping sliding contact with the bottom surface of holding tool 62 when it advances from right to left in FIG. 12. Thus the point of its spur-like shape is certain to enter between the end convolutions of the work spring that have already been spread slightly by the blade-like holding tool 62. Continued advance of the spur-shaped tool 63 toward the left causes the right curved side of the end convolution of the work spring to be cammed downward along the concave advancing edge of the tool 63 in which position it will be found ready for the anvil tool 64 to pick up and force to the left as is next to be described. In this convolution bending action of tool 63, it will be noticed in FIG. 12 that the left side of the bent convolution remains lodged against and backed up by the aforesaid shoulder 67 on tool 62.

The spur-shaped tool 63 is operated by power cam which is so shaped and fixed in such rotary position on power shaft 1 that it motivates tool 63 in the timed relation to the movement of tool 62 indicated by the diagram of FIG. 18. Cam 5 operates tool 63 by means of a cam follower arm 98 fixed on a vertical shaft 99 journaled in an upper frame bearing 122 and having also fixed thereon a crank arm 100 that reaches forward past the edge of frame plate 37. At the front of the frame plate crank arm 100 is pivotally coupled to the eyebolt of the slide that carries tool 63 by a pitman link 101. Follower arm 98 is constantly pressed against the periphery of cam 5 by spring 102. Shaft 99 extends downward and at its bottom end is journaled in a lower frame bearing 123 and thereat fixedly carries another crank arm 100' which duplicates the action of crank arm 100 as does its pitman link 101' duplicate the action of link 101 by connecting arm 100 with the slide that carries tool 63' in the lower work station 8' of the looping mechanisms.

The anvil tool 64 is shown by FIG. 18 to start into action when tool 63 has reached its convolution spreading position shown in FIG. 12. Its leading slanted edge encounters and thrusts the already separated end convolutions of the work spring from its position in FIG. '12 to its bent position in FIG. 13 and thereby into clamped engagement against the correspondingly slanted face of a clamp tool 68. Anvil tool 64 is moved from right to left by the action of power cam 7 which is so shaped and fixed in such rotary position on power shaft 1 that it motivates tool 64 in the time relation stated.

Cam 7 operates tool 64 by means of a cam follower arm fixed on a frame journaled vertical shaft 116 having also fixed thereon a crank arm 117 that reaches forward past the edge of frame plate 37. At the front of the frame plate crank arm 117 is pivotally coupled to the eyebolt of the slide that carries tool 64 by a pitman link 118. Anvil tool 64 is impelled toward the left through the mediary of the aforesaid compression spring 69. Follower arm 115 is constantly pressed against the periphery of cam 7 by spring 119. Shaft 116 extends downward and at its bottom end is again journaled in a frame bearing and thereat fixedly carries another crank arm 117 which duplicates the action of crank arm 117 as does its pitman link 118 duplicate the action of link 117 by connecting arm 117' with the slide that carries tool 64 in the lower work station S of the looping mechanisms.

Clamp tool 68 is encountered by the bent-down end convolution of the work spring when the latter is thrust against the clamp tool by and at the end of the movement of anvil tool 64 toward the left in FIG. 13. At this time, when the power shaft 1 has completed 200 degrees of its cycle of rotation, clamp tool 68 begins its travel toward the right and continues at least as far as its position in 14, pushing anvil tool 64 before it toward the right as is permitted by the yielding of thrust spring 69. The convolution that is bent to form an anchorage loop as in FIG. 13 is thus set back toward a plane diametrically aligned with the axis of the coil work spring into parallelism with which plane the anchorage loop will automatically spring back when relieved of its forced distortion and confinement between anvil tool 64 and clamp tool 68, as indicated by broken lines in FIG. 14.

Clamp tool 68 is operated to so perform by power cam 8 through the medium of a cam follower arm 124 fixed on a frame journaled vertical shaft 125 having also fixed thereon a crank arm 126 that reaches forward past the edge of frame plate 37. At the front of the frame plate crank arm 126 is pivotally coupled to the eyebolt of the slide that carries tool 68 by pitman link 127 in a manner to cause horizontal travel of the slide.

Shaft 125 extends downward and at its bottom end is again journaled in a frame bearing, and thereat fixedly carries another crank arm 126' which duplicates the action of crank arm 126 as does its driven pitman link 127 duplicate in station S the action of pitman link 127. Crank arm 126 is urged against cam 8 by a spring 128. The timing diagram of FIG. 18 shows that slide 70, which drives anvil tool 64 toward the left through the mediary of spring 69, remains stationary while tool 68 forces tool 64 toward the right against the work clamping action of spring 69 as best shown in FIG. lb and that upon reaching their positions in FIG. 14 tools 64 and 68 separate in opposite directions and resume their starting positions as in FIGS. 8, 11 and 12 at the same time that holding tool 62 withdraws from well 66 and from engagement with the coil work spring. The thus formed loop at the end of the work spring by reason of its own resilience, then automatically assumes its broken line position in FIG. 14 aligned in a diametrical plane crosswise of the coils of the work spring. Since the spur-shaped tool has previously been withdrawn to its starting position while anvil tool 64 was completing its convolution bending travel toward the left in FIG. 13, the now completely looped work spring is relieved of engagement by all of the looping tools and is freed to drop endwise out of well 66. It is received by an overturning transfer barrel 75 pivotally supported on the frame at 76 that reverses the single looped spring end for end as next to be described.

Spring OV erturning Transfer Mechanism Transfer barrel 75 contains a dead ended pocket 74 in which work spring 12 reposes when dropped therein. This pocket assumes the position previously occupied by gage 27 directly beneath well 66 immediately after the looping tools 63, 64 and 68 have withdrawn to their starting positrons and during the withdrawal of work spring holding tool 62 aforesaid.

Crown cam 9 of the power system in FIG. 3 operates transfer barrel 75 by mechanism best shown in FIGS. 15 and 17 wherein a spur gear 8-4 fixed on the frame journaled plvot shaft 76 of barrel 75 is oscillated alternately in opposite rotary directions by a gear segment 85 pivotally mounted at 59 on frame bracket 60 and that is pushed and pulled by a link 86 that extends through an opening in frame plate 37 and is pivotally coupled to a cam follower 73 of bell crank style maintained under tension against cam 9 by the spring 72 appearing in FIG. 3.

At the stage now reached, in the cycle of the machine, power shaft 1 has completed, as indicated in FIG. 18, about 300 degrees of its cycle of rotation. Thereupon after holding tool 62 has withdrawn to permit the work spring to drop into pocket 74, there is left a remaining 40 degrees of turning of the power shaft before the end of the machine cycle during which time all mechanism remains idle to allow time for a work spring to complete its dropping out of each of wells 66 and 66'. Then the actuating cams continue to rotate into position to restart the cycle of machine action represented at the extreme left of the diagram in FIG. 18.

Upon restarting the cycle of machine action, transfer barrel 75 overturns its contained work spring by swinging downward and dumping the work spring, now reversed end for end, into the'top of passageway 38' of conduit 25' of the lower work station S. This occurs at the same instant that a following unlooped work spring is dropped from chute 14 into the top end of passageway 38' in the upper work station S hereinbefore fully explained. At the same time the gage 27 again rises to take its place below the Well 66. Thus during the cycle of machine action now newly beginning and by the simultaneous operation of corresponding work handling tools in work stations S and S the first. end of a work spring becomes looped in station S while a second end of the already once looped work spring that preceeded it isbeing looped in station S so as thereby to discharge from the machine work springs looped on both ends as rapidly as successive springs are intermittently fed to the machine from chute 14.

To make possible a. very rapid overturning motion of the transfer barrel 75 without thereby flinging the work springs out of its pocket 74, the transfer barrel is equipped with a retractable end closure for its pocket 74 comprising the bentover retainer finger 77 of a rocker member 71 pivotally mounted on barrel 75 at 78- and. urged by a torsion spring 79 into a position wherein retainer finger 77 overlaps the otherwise open end of pocket 74. This position of the rocker is established by abutment of its end opposite to finger 77. against the body of the barrel near the pivotal mounting of the latter.

Finger 77 is automatically displaced from the end of pocket 74 on two occasions to give the Work spring entrance to or exit from the pocket, namely in the vertical positions thereof when respectively pointing upward and pointing downward. This is accomplished by. a lug 80 on rocker 71 that travels into abutment against a frame stationed blocking barrier 81 when barrel 75 points directly upward and by a lug 82 that travels into abutment against a frame stationed blocking barrier 83 when barrel 75 points directly downward.

Delivery Gates in the Chute The release of separate coil work springs of approximately uniform lengths for delivery from chute 14 into the top of conduit 25 one by one through the cooperative action of gates 15 and 16 has hereinbefore been briefly referred to. As best shown in FIG. 4a the aforesaid holdback gate 15 swings about a pivot 93 which may be stationed in a choice of positions along chute 1'4 afforded by a series of holes 9 4 tlierethrough. Its work springengaging end 95 bears downward against the top outer surfaceof the foremost work springcoil of theend-to-end row of springs that constantly rests in the channel of chute 14 and with suflicient staying pressure to prevent the row of coil springs from sliding down the chute until the leading spring is relieved of the pressure of end of the hold-back gate 15. Said pressure is derived by gate 15 from an axially expansive thrust spring 97 constantly compressed between a block 104 pivotally mounted to swivel on gate 15, and a collar 105 fixed on the pitman rod 112, the latter being free to slide through said block and fixed in another block 113 that swivels on gate 16. Gate 16 swings on a pivot shaft 114 that is journaled through the body of chute 14 and that carries a crank arm at the rear of the chute, arm 120 being pivotally connected to the pitman link 129 which in turn is pivotally connected to the upstanding crank arm '18 fixed on shaft 54. The detent nose of gate 16 alternately enters downward and withdraws upward out of the channel 96 of chute 14 as gate 16 is swung respectively clockwise and counterclockwise in FIG. 4a. A second collar 121 is fixed on rod 103 to actuate gate 15 in clockwise direction.

When crank arm 120 swings gates 15 and 16 clockwise the release gate 16 blocks a first work spring that has been released by the hold-back gate 15. When crank arm 120 swings gates 15 and 16 counterclockwise gate 15 retainingly clamps the following work spring and gate 16 clears out of the path of the first work spring so that this single spring alone escapes and drops out of the chute into conduit 25.

Operation of Complete Machine The operation of my improved looping machine as a whole can best be summarized and outlined with reference to FIG. 18, where. the following relative times of action of the coordinated work handling mechanisms are indicated. Assuming as aforesaid that the left end of the operational diagrams represents the common instantaneous start of the machine cycle, with the exception of the actions of the chute feeding escapement gates 15 and 16 that are coordinated and contemporary with the spring overturning and transfer action of the barrel 75, each of the work handling mechanisms in lower station S perform simultaneously with the corresponding mechanisms in upper Work station S wherefore it henceforth will be necessary to mention only the mechanisms in upper station S.

Simultaneously during the first 60, of the 360 total cycle of continual turning of power shaft 1, transfer barrel 75 flips to down pointing position, gage 27 swings forward and upward 'to take its place directly below Well 66, and conduit 25 and its work engaging clutch fingers 26 rise while rotating idly. During this time the escapement gates 15 and 16 cause one unlooped coil work spring to drop into the conduit 25 and the transfer barrel 75 turns end for end and dumps 21 thus reversed work spring already looped at one end into the conduit 25'. All mechanisms remain idle for the next 40 or 45 degrees of turning of the power shaft whereupon the direction of spinning of conduit '25 and its clutch fingers 26 takes place in opposite rotary direction as the conduit 25 descends during which time clutch fingers 26 close in lightly on the work spring and place it in well 66 resting in predetermined rotary position on gage 27 ready to be looped. At this time, or after the power shaft has completed some degrees of its cycle of rotation, the loop forming tools 62, 63, 64 and 68' perform successive movement in part simultaneously as hereinb'efore fully described. Retnaotion of the gage begins after the power shaft has completed 200 degrees" of its cycle and restoration of the transfer barrel into work spring receiving position begins when the power shaft has completed 230 degrees of the cycle. When the power shaft has performed 320 degrees of its cycle of movement the tools have completed their loop forming functions and permit the work spring in station S to drop from well 66 into the pocket 74 in transfer barrel 75 which has been restored as abovesaid to position under well 66 to receive the work spring just following the retraction of gage 27 from occupancy of that position. At the same time a finished work spring looped on each end is discharged downward from well 66 in station S.

The appended claims are intended not to be limited in coverage to the exact details of structure and arrangement herein illustrated and described for teaching the principles and functioning of a machine embodying the invention, but contemplate in their scope all mechanical equivalents therefor known to the art in which the inventive principles of the improvements may be embodied.

I claim:

1. Mechanism for advancing to and lodging in predetermined rotary and axial position a coil work spring to be looped, comprising in combination with frame hearing structure, a downward directed conduit encompassing a rectilinear passageway open at both top and bottom ends for guiding the coil work spring to said axial position and journaled in said bearing structure with freedom to slide axially therein, means to rotate said conduit, means to reciprocate said conduit alternately in opposite axial directions, clutch fingers carried by said conduit movable into and out of positions for engagement with a coil work spring occupying said passageway, and cam action connections cooperatively associating said clutch fingers with said bearing structure in such manner that axial sliding of said conduit causes shifting of said fingers into and out of their said work spring engaging positions as said conduit both reciprocates and rotates together with a shouldered support gage located at an end of said conduit in position to be engaged by and orient the work spring when released by said fingers.

2. Mechanism las defined in claim 1, in which the said connections include cam surfaces on the said clutch fingers, and further include cam wipers respectively cooperative therewith stationed axially in relation to the said bearing structure, whereby relative movement between said cam surfaces and wipers is caused by axial sliding of the said conduit in a manner to cause the said shifting of said clutch fingers.

3. Mechanism as defined in claim 1, in which the said connections cause the said clutch fingers to shift into their said work spring engaging positions only in a range of positions intermediate both the upward and downward limits of sliding movement of the said conduit, whereby said fingers are encountered by the end of a coil work spring dropping through the said passageway during said upward movement of the conduit and frictionally clutch the outer contour of said work spring and rotate the latter during said downward movement of the conduit.

4. Mechanism as defined in claim 1, in which the said connections include cam surfaces on the said clutch fingers and cam wipers respectively cooperating therewith, together with supplemental bearing structure cooperating with said wipers to prevent movement thereof axially of said conduit while said wipers rotate in unison with the said conduit.

5. Mechanism as defined in claim 4, in which the said conduit contains external keyways angularly spaced in accordance with the said clutch fingers, and the said cam wipers comprise keys slidably nested in said keyways respectively.

6. Mechanism as defined in claim 5, in which each of the said keys has a radially outward projecting lug and the said supplemental bearing structure includes an annular thrust resisting raceway in which the said lug is free to revolve in unison with rotation of the said conduit while stayed against axial movement by said raceway.

7. Mechanism as defined in claim 1, in which the said connections cause the said clutch fingers to shift into their said work spring engaging positions only at a range of positions intermediate the limits of axial sliding movement of the said conduit, whereby said work spring is cleared of engagement by said fingers at both the upper and lower limits of said sliding movement of the conduit.

8. Mechanism as defined in claim 7, together with resilient means constantly biasing the said clutch fingers to shift into their said work spring engaging posiuon whereby to exert a yielding pressure thereagainst causing light frictional grasp of the work Spring by said fingers.

9. Mechanism as defined in claim 7, together with work spring feeding means connected to operate in timed relation to the vertical sliding movement of the said conduit in a manner to drop a work spring endwise into the said passageway :of the said conduit at a time to be arrested by the said clutch fingers on its way downward through said passageway during rising travel of said conduit.

10. Mechanism as defined in claim 1, together with power means connected to motivate simultaneously the said means to rotate said conduit and the said means to reciprocate said conduit whereby helical downward movement is yield-ingly imparted to a coil work spring engaged by the said clutch fingers while in said conduit.

11. Mechanism as defined in claim 10, together with a work spring trapping device comprising, a stationary shallow well coaxially aligned with and closely underlying the said bottom open end of the said passageway through the said reciprocated conduit, and a support gage closely underlying the bottom of said well presenting an upward directed radially shouldered face operative to encounter and withstand the downward thrust of the coil work spring and also the turning tendency thereof yieldingly imparted thereto by helical travel of the said clutch fingers.

12. Mechanism as defined in claim 11, together with a movable carrier on which the said support gage is mounted, said carrier being shiftable in an arcuate direction in a plane parallel with the axis of the said conduit between limits of movement in which the said gage respectively is in position to close the bottom of the said well and is retracted sufficiently from said position to free the said work spring and permit it to drop down ward out of said well.

13. The combination with mechanism as defined in claim 11, of a like mechanism positioned therebelow in such alignment therewith that the said passageway of the said conduit in said like mechanism is in coaxial alignment with the said spring trapping well and with the passageway of the said reciprocated conduit in the superimposed mechanism, together with a receptacle underlying said well in position to receive a work spring looped at one end when dropped from said well, said receptacle being pivotally mounted to perform approximately a half turn about a pivot stationed between said well and the open top end of the said conduit of the said like mechanism therebelow and in line with the common axis of the said conduits, whereby turning of said receptacle when carrying said work spring will reverse the latter end-forend and discharge the work spring thus reversed into said coaxial conduit passageway of said like mechanism.

14. Mechanism for transferring a coil work spring from frame joined upper and lower stations in a coil spring looping machine comprising the combination defined in claim 13, together with a work spring retainer movably mounted on the said receptacle in a manner to shift to and from a position so closing the open end of said receptacle as to prevent both entrance and departure of said work spring therefrom, and means to displace said retainer from said position arranged to be actuated by turning movement of said receptacle.

15. Mechanism as defined in claim 14, in which the said retainer has a pivotal mounting on the said receptacle about which said retainer rocks to and away from a position overlapping the said open end of said receptacle, and resilient means biasing said retainer to rock toward said position;

16. Mechanism as defined in claim 15, in which the said retainer has terminals on opposite sides of the pivotal mounting of the said receptacle, together with separate abutments stationed on opposite sides of said pivotal mounting of said receptacle in position to encounter and References Cited in the file of this patent UNITED STATES PATENTS Conner etal Sept. 19, 1899 Harter Dec. 8, 1908 Harter Jan. 28, 1913 Sleeper Dec. 30, 1913 14 Flaherty Aug. 22, 1916 Dunkley Dec. 22, 1931 Ba er Apr. 27, 1937 Curtis Jan. 9, 1940' Clauss May 27, 1941 Tiedemann Nov. 3, 1942 Malewicz Apr. 29, 1958 Louden Apr. 21, 1959 FOREIGN PATENTS Norway June 20, 1898 

